/* Sticky instruments belong to their reading section and release at its end. */
.site-brand{display:flex!important;align-items:center;gap:12px;text-decoration:none}.site-brand-mark{display:grid;place-items:center;flex:0 0 40px;width:40px;height:40px;border:1px solid #b2c6b6;border-radius:50%;font-family:Georgia,serif;font-size:22px;color:#edf2e8}.site-brand-wordmark{display:flex;flex-direction:column;gap:4px}.site-brand-wordmark strong,.site-brand-wordmark small{display:block}.overview-hero{padding-bottom:6px!important}.chapter-nav{padding-top:14px!important;padding-bottom:8px!important;margin-bottom:0!important}#systems{margin-top:12px;padding-top:28px}.system-layout,.sky-layout,.phenomenon-layout{align-items:start}.world-interactive-pin,.sky-layout .visual-column.world-interactive-pin{position:sticky;top:24px;align-self:start;min-width:0;z-index:5}.world-map-reading-layout{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(260px,.85fr);gap:32px;align-items:start}.world-map-copy{min-width:0}.world-map-visual .toolbar{margin-top:0}.world-map-visual .map-stage{margin-top:12px}.world-map-copy .geography-notes{display:block}.world-map-copy .geography-notes>*+*{margin-top:24px}.world-map-copy .selected-note{margin-top:0}.world-map-visual{background:var(--paper,#f7f7f2)}
@media(max-width:760px){.world-map-reading-layout{display:block}.world-interactive-pin,.sky-layout .visual-column.world-interactive-pin{top:8px;z-index:35;background:var(--paper,#f7f7f2);padding:8px 0 10px;box-shadow:0 10px 16px -16px #16372d}.world-map-copy{padding-top:20px}.world-interactive-pin .model-controls{margin:8px 0 0;gap:10px}.world-interactive-pin .tabs{margin-bottom:10px}.world-interactive-pin #phenomenonFigure img{max-height:29svh;width:100%;object-fit:contain}.world-interactive-pin .model-controls button{padding:8px 12px}.world-interactive-pin .model-controls label{font-size:13px}.world-interactive-pin input[type=range]{width:80px}.world-map-visual .toolbar{padding:0;margin-bottom:8px}.site-brand-mark{flex-basis:36px;width:36px;height:36px}.world-map-visual .map-stage{margin:0}.world-map-visual{margin-bottom:12px}}
@media(max-width:760px){.world-interactive-pin .orrery{width:min(100%,calc(26svh * 1.3333));margin:10px auto;aspect-ratio:1000/750}.world-interactive-pin .world-sky-stage{width:min(100%,calc(29svh * 12 / 7));margin:10px auto 0}.world-map-visual .map-stage{width:min(100%,64svh);margin:0 auto}.world-interactive-pin .switches{margin-bottom:0}}
@media(max-width:760px) and (max-height:560px){.world-interactive-pin,.sky-layout .visual-column.world-interactive-pin{position:relative;top:auto}}

/* Larger phone map: retain the projection, pan horizontally within half-screen. */
@media(max-width:760px){.world-map-visual .map-stage{width:100%;height:clamp(180px,calc(50svh - 94px),420px);overflow-x:auto;overflow-y:hidden;overscroll-behavior-x:contain;-webkit-overflow-scrolling:touch}.world-map-visual .map-stage svg{width:max(100%,calc(clamp(180px,calc(50svh - 94px),420px) * 2));height:100%;max-width:none;touch-action:pan-x pan-y}.world-map-visual::after{content:"左右滑动查看全图，双指缩放，拖动查看细节";display:block;font-size:12px;line-height:20px;color:var(--muted);padding-top:4px}}

/* The cover spans the reading column while introductory text keeps its measure. */
@media(min-width:1100px){.overview-hero{box-sizing:border-box;width:100%;max-width:none}.overview-hero>.prose{max-width:1080px}}
@media(min-width:1900px){.overview-hero>.prose{max-width:1150px}}

/* Full-bleed overview cover, independent of the reading column and its directory. */
.overview-hero.world-cover-hero{box-sizing:border-box;display:flex;align-items:center;width:100%;max-width:none;min-height:clamp(520px,70svh,760px);margin:0;padding:0!important;background:#091819}
.world-cover-inner{box-sizing:border-box;width:calc(100% - 48px);max-width:1360px;margin:0 auto;padding:76px 0 112px}
.world-cover-inner>.prose{max-width:760px}.world-cover-inner>.deck{max-width:760px}.world-cover-inner>.kicker{margin-top:0}

.chapter-nav.world-cover-nav{box-sizing:border-box;margin:0 0 16px;padding:18px 0!important;border-top:0;border-bottom:1px solid var(--line);background:var(--paper,#f6f7f0);color:var(--ink)}
@media(min-width:1600px){.overview-hero.world-cover-hero::before{background-image:linear-gradient(90deg,rgb(7 18 20 / .9),rgb(7 18 20 / var(--bth-header-overlay,.66)) 55%,rgb(7 18 20 / .18)),var(--bth-header-image)}}
@media(max-width:760px){.overview-hero.world-cover-hero{min-height:0}.world-cover-inner{width:calc(100% - 40px);padding:44px 0 90px}.chapter-nav.world-cover-nav{gap:12px 20px;padding:16px 0!important}}

/* No repeated rules between the cover navigation and the first chapter. */
.chapter-nav.world-cover-nav+#systems{border-top:0}

.region-custom-copy{white-space:normal}

/* Keep chapter introductions readable; use parallel paragraphs on wide screens. */
@media(min-width:1100px){
 #sky>.sky-preface,#surface>.surface-copy{max-width:48em}
 #surface>.map-instruction{max-width:52em}
}
@media(min-width:1440px){
 #sky>.sky-preface,#surface>.surface-copy{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));column-gap:clamp(32px,3vw,64px);align-items:start;max-width:1440px}
 #sky>.sky-preface>[data-content-id],#surface>.surface-copy>[data-content-id]{min-width:0;max-width:44em}
 #sky>.sky-preface>[data-content-id]:first-child,#surface>.surface-copy>[data-content-id]:first-child{grid-column:1/-1;max-width:52em}
}

/* Sky hierarchy is scoped to the overview chapter. */
#sky .sky-lead,#sky .sky-far>.prose{max-width:64em}#sky .sky-hemispheres>h3{font-size:clamp(26px,3vw,36px);margin:32px 0 24px}#sky .sky-near>h4,#sky .sky-far>h4{font-size:clamp(23px,2.5vw,30px);margin:32px 0 22px}#sky .sky-phenomenon-heading{font-size:clamp(22px,2.3vw,29px);margin:34px 0 22px}#sky #skyTitle{font-size:clamp(21px,2vw,28px);margin:14px 0}#sky .sky-far{margin-top:36px;padding-top:26px;border-top:1px solid var(--line)}#sky .sky-hemispheres,#sky .sky-near,#sky .sky-far,#sky .sky-phenomenon-heading{scroll-margin-top:28px}@media(max-width:760px){#sky .sky-near>h4,#sky .sky-far>h4{margin-top:26px}}

/* Sky title hierarchy: chapter, shared topic, hemisphere, phenomenon. */
#sky>.chapter-heading h2{font-size:clamp(32px,3.5vw,46px);font-weight:500;line-height:1.25}
#sky .sky-hemispheres>h3{font-size:clamp(28px,2.8vw,36px);font-weight:600;line-height:1.35;margin:44px 0 26px;padding-bottom:14px;border-bottom:1px solid var(--line)}
#sky .sky-near>h4,#sky .sky-far>h4{font-size:clamp(24px,2.2vw,29px);font-weight:600;line-height:1.4;margin:36px 0 24px}
#sky .sky-phenomenon-heading,#sky [data-devia-day] .dpd-heading h5{font-family:inherit;font-size:clamp(21px,1.8vw,24px);font-weight:600;line-height:1.45;letter-spacing:0;margin:28px 0 18px;color:var(--ink)}
#sky #skyTitle{font-size:clamp(20px,1.65vw,23px);font-weight:500;line-height:1.45;margin:12px 0 18px}
#sky .sky-far-reference{max-width:900px;margin:24px 0 0}#sky .sky-far-reference figure{margin:0}#sky .sky-far-reference img{display:block;width:100%;height:auto;border-radius:8px}#sky .sky-far-reference figcaption{color:var(--muted);font-size:.88em;line-height:1.6;margin-top:10px}
@media(max-width:760px){#sky .sky-hemispheres>h3{margin-top:32px;padding-bottom:12px}#sky .sky-near>h4,#sky .sky-far>h4{margin:28px 0 20px}#sky .sky-phenomenon-heading,#sky [data-devia-day] .dpd-heading h5{margin:24px 0 16px}}

/* Align the hemisphere map with its explanation and orbit diagram. */
#sky .sky-hemispheres > .moon-range,
#sky .sky-hemispheres > .sky-hemisphere-reading {
  width: min(100%, 1050px);
  margin-inline: auto;
}
#sky .sky-hemispheres > .moon-range {
  margin-block: 0 clamp(20px, 3vw, 36px);
}
#sky .sky-hemispheres > .moon-range img {
  margin: 0;
}
#sky .sky-hemisphere-reading {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  align-items: start;
}
#sky .sky-hemisphere-reading > .sky-explanation {
  min-width: 0;
  max-width: 64em;
}
#sky .sky-hemisphere-reading > .sky-explanation > :first-child {
  margin-top: 0;
}
#sky .sky-hemisphere-reading > .sky-explanation > :last-child {
  margin-bottom: 0;
}
#sky .sky-hemisphere-reading > .sky-tidal-view {
  width: min(100%, 380px);
  margin-inline: auto;
}
#sky .sky-hemisphere-reading [data-tidal-lock-view] {
  margin: 0;
}
@media (min-width: 1000px) {
  #sky .sky-hemisphere-reading {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 36%);
  }
  #sky .sky-hemisphere-reading > .sky-tidal-view {
    width: 100%;
  }
}

#sky .sky-near-intro {
  max-width: 64em;
  margin: 0 0 20px;
  color: var(--muted);
  font-size: clamp(14px, 1.1vw, 16px);
  line-height: 1.95;
}